Carburetor for internal combustion engine

ABSTRACT

Oppositely disposed downwardly and inwardly extending concave side walls in main air passage of carburetor below throttle terminating in spaced relation to each other to define elongated opening therebetween which extends transversely of air passage and parallel to side walls. Side walls direct oppositely disposed streams consisting of fuel and air toward each other prior to passing through elongated opening.

United States Patent 1 1 3,707,278 Landrum 1 1 Dec. 26, 1972 s41CARBURETOR FOR INTERNAL 723,206 3/1903 Lukenba ch 261/78 R COMBUSTIONENGINE 2,831,666 4/1958 Compton 261/78 R 1 3,467,072 9/1969 Toesca261/78 R [72] Invent: Landrum, Blrmmgham, A 1,437,423 12/1922 Jackson48/180 R Assignees: Porter Landrum Y. Landrurn 1 McMon-ies; MrsLMm-sha"Timber, 2,175,438 10/1939 Mannmg ..123/52 M 2,618,541 11/1952 A eman eta1... ..123/4ll gr l,361,260 12/1928 Hunt ..48/l80 R McMmles, BirminghamFOREIGN PATENTS OR APPLICATIONS a part interest to each l .4818 R 22Filed: 0 1.26, 1970 "25mm 0 [21] Appl. No.: 83,717 Primary Examiner-TimR. Miles Attorney-Jennings, Carter & Thompson [52.] US. Cl ..261/62,261/78 Riga/818k [57] ABSTRACT [51] Int. Cl ..F02m 29/14 oppositelydisposed downwardly and inwardly extend- Field of Search 8 180 130 M;ing concave side walls in main air passage of carbure- 26l/76,7 123/141tor below throttle tenninating in spaced relation to each other todefine elongated opening therebetween References Cited which extendstransversely of air passage and parallel UNITED STATES PATENTS to sidewalls Side walls direct oppositely disposed v streams cons1st1ng of fueland air toward each other 3,393,984 7/1968 Wisman ..26l/78 R prior topassing through elongated opening. 1,406,398 2/1922 Livingston.....'....48/l80 R 1,711,496 5/1929 Heald ..48/1 80 B 10 Claims, 8 DrawingFigures W /a I 1 i 7 l /9 1* 22 ma PATENTED DEC 26 1972 SHEET 1 UP 2INVENTOR. orzer Z andrum PATENTEDunczs 1972 SHEET 2 OF 2 INVENTOR.Porter am/r um CARBURETOR FOR INTERNAL COMBUSTION a ENGINE BACKGROUND OFTHE INVENTION This invention relates to carburetors for internalcombustion engines and more particularly to improved means for atomizingthe fuel air mixture just prior to introduction of the mixture into theintake manifold of the, engine to obtain more complete combustionthereby greatly reducing air pollution and bringing about a substantialsaving in fuel.

As is well known in the art to which my invention relates, the burningefficiency under pressure of the fuelair mixture is directly affected bythe fineness of atomization of the gasoline by the carburetor. Whilemany devices have been proposed for atomizing'the gasoline by thecarburetor, such devices have not been effective to bring about thedegree of atomization required to cause substantially completecombustion of the fuel.

BRIEF SUMMARY OF THE INVENTION In accordance with my present invention,I provide oppositely disposed, downwardly and inwardly extending concaveside walls for the main air passage of the carburetor below the throttlevalve. The concave sidewalls terminate in spaced relation to each otherat their lower ends to provide an elongated opening between the sidewalls which extends transversely of the air passage and parallel to theside walls. As the air-fuel mixture moves downwardly and inwardly alongthe inner surfaces of the concave side walls, the streams are directedtoward each other whereby there is a head on contact of the two streamswith each other which brings about increased agitation and atomizationof the fuel-air streams immediately prior to a 90 change in direction ofmovement of the streams through the elongated Opening into the engineintake where the fuel-air mixture expands prior to being drawn into thecylinder.

Carburetors illustrating features of my invention are shown in theaccompanying drawing, forming a part of this application, in which:

FIG. 1 is a vertical cross sectional view of a somewhat standard downdraft carburetor having my invention applied thereto and showing thethrottle valve in closed position;

FIG. 2 is a fragmental, vertical sectional view corresponding to FIG. 1showing the throttle in partially open position;

FIG. 3 is a fragmental, vertical sectional view, corresponding to FIG. 2showing the throttle in fully open position;

FIG. 4 is a view taken generally along the line 44 of FIG. 1;

FIG. 5 is a fragmental view taken generally along the line 5-5 of FIG.1;

FIG. 6 is a fragmental, vertical sectional view showing the lower partof a carburetor embodying a modified form of my invention;

FIG. 7 is a top plan view, partly broken away, taken generally along theline 7-7 of FIG. 6; and,

FIG. 8 is a fragmental sectional view showing a further modified form ofmy invention.

Referring now to the drawings for a better understanding of myinvention, I show in FIGS. 1 through 5 a carburetor 10 having a main airpassage 11 including a venturi opening 12 of a predetermined area. A

butterfly throttle valve 13 is mounted-for pivotal movement in the airpassage 11 in the usual manner downstream from the venturi opening 12,as shown. A restricted idle port 14 communicates with the air passage'11 downstream from the throttle 13 when the throttle is in closedposition, as shown in FIG. 1. An idling adjustment screw 16 cooperateswith the idle port to regulate the flow of the air-fuel mixture aroundthe butterfly throttle valve 13.

As shown in FIGS. 1, 2 and 3, the air passageway 11 terminates inoppositely disposed, downwardly and inwardly extending side walls 17 and18 downstream from the idle port 14. The inner surface of the downwardlyand inwardly extending side walls 17 and 18 is concave, as shown, withthe lower ends of the side walls 17 and 18 terminating in spacedrelationto each other to define an elongated opening 19 which extends ina vertical plane in vertical alignment with the air passageway 11.Accordingly, the air-fuel mixture passing downwardly alongside theconcave side walls 17 and 18, as shown in FIGS. 2. and 3, is directedinwardly whereby the oppositely disposed streams meet head onimmediately prior to making a right angle turn for passage downwardlythrough the elongated opening 19. That'is, the oppositely disposedconcave side walls 17 and 18 direct the two streams consisting of fueland air toward each other adjacent the lower ends of the side walls 17and 18 whereby they meet head on to bring about increased agitation andmixing of the air and fuel particles immediately prior to movement ofthe combined streams'downwardly through the elongated opening 19. Eachelongated Opening 19 extends transversely of the air passage 11 andgenerallyparallel to the side walls whereby the downwardly movingstreams move over the longer sides of the elongated opening 19.

The elongated opening 19 extends substantially the entire width of theair passage 11 and the thickness of the material through which opening19 is formed is equal substantially the width of the elongated opening19. Inactual practice, I have found that satisfactory results areobtained where the side walls of each open ing 19 are approximatelyone-quarter inch in depth. By providing the A inch depth for theelongated opening 19, the air-fuel mixture is maintained in aconcentrated condition at a very high velocity for a sufficient lengthof time to bring about intimately mixing of the air-fuel mixture. Uponleaving the elongated opening 19, the air-fuel mixture passes into theintake port 21 for the engine where the mixture is expanded in the usualmanner. Preferably, the portion of the carburetor carrying theoppositely disposed, downwardly and inwardly extending side walls 17 and18 and the elongated opening 19 is formed of a separate member 10a whichmay be attached to the lower end of a conventional type carburetor, thusfacilitating modification of conventional carburetors to accommodate myinvention.

' As shown in FIGS. 1, 2, 3 and 4, the'lower portion of each downwardlyand inwardly extending side wall 17 and 18 terminates in a flat portion22 adjacent the periphery of the elongated opening 19. Preferably, theflat portion 22 is approximately three thirty-seconds of an inch inwidth. By providing the flat portion 22 around the periphery of eachelongated'opening' 19, the oppositely disposed streams consisting of thefuel-air mixture move in a direction perpendicular to the side walls ofthe opening 19 or perpendicular to a vertica plane passing through theopenings 19.

In FIG. 8 of the drawings, I show a modified form of my invention inwhich the oppositely disposed side walls 17 and 18 arecurved all the wayto the openings 19 and are not-provided with the flat peripheral flatsurfaces 22. Accordingly, the oppositely disposed streams moving downthe concave side walls 17 and 18 move in an arcuate path into head onengagement with each other and then move downwardly through theelongated opening, as described hereinabove.

In FIGS.6 and 7, l show a further modified form of my invention in whichone of the oppositely disposed, downwardly and inwardly extending sidewalls, indicated at 170, is movable relative to a' stationary,downwardly and inwardly extending side wall 18a. That is, at highspeeds, it is often desirable to increase the area of the "elongatedrestricted opening 19 upon a. predetermined differential in pressurewithin the air passage atopposite sides of the opening 19. To accomplishthis, I provide a movable member 23 which is pivotally connected by apivot pin 24 tonne side of the member a. A suitable recess 26 isprovided in the member 10a for receiving the movable member 13.

. The concave surface 17a is provided along the inner surface of themovable member 23 whereby the oppositely disposed streams movedownwardly and inwardly into head-on contact with each other immediatelyprior to moving downwardly through the elongated restricted opening 19,as described hereinabove. A compression spring 27 is interposed betweenthe movable member 23 and the bottom of a recess 28 provided in themember 10a, as shown in FIG. 6, whereby the lower free end of themovable member 23 is urged upwardly to the solid line position. Upon apredetermined differential in pressure within the air-fuel passageway 11at opposite sides'of the opening 19, the lower end of the movable member23 is moved downwardly toward the dotted line position shown in FIG. 6,whereby the effective area of the elongated opening 19 is increased. Thelower ends of the downwardly and inwardly extending side walls 17a and18a terminate in flat portions 22 to further direct the streams intohead on contact with each other, as described above.

From the foregoing,-it will be seen that I have devised an improvedmeans for atomizing a fuel-air mixture as it passes from the carburetorinto the intake of an internal combustion engine. By providing theoppositely disposed, downwardly and inwardly extending side walls 17 and18, the oppositely disposed streams move into head on contact with eachother to thus increase agitation and atomization of the fuel immediatelyprior to moving in a 90 direction downwardly through the elongatedopening 19 thus greatly reducing air pollution and at the same timebringing about a substantial saving in fuel. By providing side walls ofapproximately one-fourth inch for the elongated opening 19, the atomizedstream is held in a concentrated condition at extremely high velocitieslong enough to intimately mix thefuel and air particles whereby uponmoving into the enlarged area of the intake port 21, substantiallycomplete atomization of the air-fuel mixture is obtained. Furthermore,by providing a movable side wall for the elongated opening 19, theeffective area of the opening 19 is varied in response to predeterminedincreases in pressure within the air passageway 11.

In actual practice, I have found that a carburetor having a venturiopening 12 of a diameter of approximately 1.02 square inch and anelongated opening 19 of an area equal substantially 0.468 square inch issatisfactory in every respect. Also, a carburetor having a venturi of adiameter of approximately 1.093 square inch and an elongated opening 19ofan area equal substantially 0.485 square inch is satisfactory in everynot substantially greater than the area of the venturi opening andpreferably should be less than one-half of the area of the venturiopening. The length of the elongated opening 19 should be as long as thethrottle body bore permits, thus reducing the width of the opening.

In actual practice, I have found that the carbon monoxide andhydrocarbon gases in the engine exhaust are greatly reduced where myimproved means is employed for agitating the fuel-air mixture.Furthermore, my invention brings about a material saving in fuel.

While I have shown my invention in several forms, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various other changes and 30 modifications without departing from thespirit thereof.

What I claim is: I. In a carburetor having a main air passage for con- Iveying fuel and air to the intake of an internal combustion engine andincluding a venturi opening of a predetermined area, a throttle in saidair passage downstream from said venturi opening and a restricted idleport in said air passage downstream from said throttle when saidthrottle is in closed position,

a. downwardly and inwardly curved side walls at opposite sides of saidair passage downstream from said idle port terminating in spacedrelation to each other with each said side wall being concave adjacentthe lower portion thereof and directing oppositely disposed streamsconsisting of fuel and air toward each other adjacent the lower ends ofsaid side walls, and

b. an elongated restricted opening extending transversely of said airpassage with the sides thereof generally parallel to said concave sidewalls and defined between said lower ends of said side walls so thatsaid oppositely disposed streams move over the longer sides of saidelongated opening immediately prior to making sudden changes indirection of movement and said elongated opening having an area lessthan the area of said venturi opening and less than the area of saidintake and being of a depth to maintain the streams of air and fuel in aconcentrated condition at a high velocity for a sufficient length oftime to bring about intimate mixing of said streams of air and fuel.

2. A carburetor as defined in claim 1 in which said elongated openingextends substantially the entire width of said air passage.

3. A carburetor as defined in claim 1 in which the area of saidelongated opening is less than one half the area of said venturiopening.

respect. The elongated opening 19 should be of an area' 4. A carburetoras defined in claim 1 in which the lower ends of said side walls extendgenerally perpendicular to a verticle plane passing through saidelongated opening.

5. A carburetor as defined in claim 4 in which the lower ends of saidside walls terminate in flat surfaces adjacent said elongated opening.

6. A carburetor as defined in claim 1 in which at least one of said sidewalls is movable relative to the other side wall upon a predetermineddifferential inpressure within said air passage at opposite sides ofsaid elongated opening.

7. A carburetor as defined in claim 6 in which the

1. In a carburetor having a main air passage for conveying fuel and airto the intake of an internal combustion engine and including a venturiopening of a predetermined area, a throttle in said air passagedownstream from said venturi opening and a restricted idle port in saidair passage downstream from said throttle when said throttle is inclosed position, a. downwardly and inwardly curved side walls atopposite sides of said air passage downstream from said idle portterminating in spaced relation to each other with each said side wallbeing concave adjacent the lower portion thereof and directingoppositely disposed streams consisting of fuel and air toward each otheradjacent the lower ends of said side walls, and b. an elongatedrestricted opening extending transversely of said air passage with thesides thereof generally parallel to said concave side walls and definedbetween said lower ends of said side walls so that said oppositelydisposed streams move over the longer sides of said elongated openingimmediately prior to making sudden changes in direction of movement andsaid elongated opening having an area less than the area of said venturiopening and less than the area of said intake and being of a depth tomaintain the streams of air and fuel in a concentrated condition at ahigh velocity for a sufficient length of time to bring about intimatemixing of said streams of air and fuel.
 2. A carburetor as defined inclaim 1 in which said elongated opening extends substantially the entirewidth of said air passage.
 3. A carburetor as defined in claim 1 inwhich the area of said elongated opening is less than one half the areaof said venturi opening.
 4. A carburetor as defined in claim 1 in whichthe lower ends of said side walls extend generally perpendicular to averticle plane passing through said elongated opening.
 5. A carburetoras defined in claim 4 in which the lower ends of said side wallsterminate in flat surfaces adjacent said elongated opening.
 6. Acarburetor as defined in claim 1 in which at least one of said sidewalls is movable relative to the other side wall upon a predetermineddifferential in pressure within said air passage at opposite sides ofsaid elongated opening.
 7. A carburetor as defined in claim 6 in whichthe movable side wall is mounted for pivotal movement adjacent its upperend with the lower end thereof being movable.
 8. A carburetor as definedin claim 7 in which a spring member urges said lower end of said movableside wall toward an upper position.
 9. A carburetor as defined in claim1 in which said elongated opening has side walls of a depth equalsubstantially the width of said opening.
 10. A carburetor as defined inclaim 9 in which said elongated opening has side walls approximatelyone-fourth inch in depth.